Phenomenon of domination of the strongest contacts in centric occlusion.

Objective: The number and distribution of occlusal contacts in centric occlusion (CO) and centric relation have been studied by a number of authors. All these studies have one thing in common--they define the greatest number of occlusal contacts between the molars. The purpose of the present study was to register the maximum clenching forces in CO, as well as to analyze the anatomic and functional factors that determine their localization on teeth.

Method And Materials: The study included 42 subjects, aged 19 to 26 years, with intact dentition and Class I Angle occlusion; 38 persons had 1 to 4 restorations on the premolars and molars. The occlusal contacts were investigated in CO by the T-Scan system (Sentek) on wax and silicone impressions. The force loads in different sections of the dentition were differentiated by an additionally developed computer program.

Results: The T-Scan analysis and the developed computer program revealed that the maximum values of the clenching forces were recorded on the third molars. The strongest contacts found by the T-Scan system were successfully visualized in wax and silicone impressions.

Conclusion: The maximum clenching forces of the masticatory muscles recorded by the T-Scan system were located in CO at the third molars in a dentition of 32 teeth and at the second molars in a dentition of 28 teeth. If the above-mentioned phenomenon is not taken into consideration in clinical practice, occlusal contacts may be created that will unfavorably transfer the specific clenching forces to a more medially located molar in cases of occlusal restoration of the same molar by a restoration or a single crown.